GA-fan

There is no solidly right or wrong answer to this question, because it basically doesn't matter. No firm will think less of you for emailing thank you's or sending just one letter to the recruiting coordinator- just do whatever you feel comfortable with. And know that in the end, it probably won't make a hill of beans difference in whether you get the offer- it just comes down to showing sincere gratitude to the firm for taking the time to interview you and spending a boat load of money for taking you to dinner, lunch, etc.